It’s been a few years since I measured any rockers for ratio correctness.
The last ones were Jesel 1.7’s on Indy 572-13’s....... I don’t remember what the exact numbers were, but the gist of what I saw was there wasn’t any “extra” ratio built in.......and that with 800lbs open load they did lose a little....... but not much.

The farthest off on the high side I’ve measured were some HS 1.6’s on a set of Indy SR’s.
1.67 with checking springs and still about 1.63 with 700lbs spring load.

I’ve tested several BBM rockers that lost over .05 ratio going from checking springs to full spring load.